Real-time spectrum analyzers such as the RSA6100 and RSA3400 families available from Tektronix, Inc. of Beaverton, Oreg. trigger on, capture, and analyze RF signals in real-time. These test and measurement instruments seamlessly capture RF signals so that, unlike conventional swept spectrum analyzers and vector signal analyzers, no data is missed within a specified bandwidth.
Real-time spectrum analyzers commonly display acquired data on a decibel (dB) scale. A dB scale is calculated as 10×log10(P2/P1), where P2 is the power of the signal under test, and P1 is a reference power. However, on a dB scale, low power signals may appear at discrete levels separated by gaps due to the finite resolution of the acquired data and the logarithmic conversion. This display artifact, referred to as “intensity banding,” can be very objectionable. As an example, FIG. 1 shows a pulsed RF signal 105 on a dB scale. The pulsed RF signal 105 is represented by 18-bit data, and as a result, power levels below −75 dB appear at discrete levels 110. Intensity banding can be reduced by using more bits to represent the signal under test, for example, by using a higher resolution analog-to-digital converter, however in many cases, a higher resolution analog-to-digital converter is not available or other system considerations limit the number of available bits.
What is desired is a way of displaying acquired data on a logarithmic scale without intensity banding.